An electric vehicle (EV) charging system may basically be defined as a system for charging a high-voltage battery mounted on an EV by using power of an energy storage device or a power grid of a commercial power source. Such the EV charging system may have various forms according to the type of EV. For example, the EV charging system may be classified into a conductive charging type using a charging cable and a non-contact wireless power transfer (WPT) type (also referred to as an ‘inductive charging type’).
In the case of inductive charging using a WPT system, when it is necessary to charge the high-voltage battery mounted on the EV, the EV may move to a ground assembly (GA) located in a charging station or a charging spot capable of EV charging.
When charging the EV, a vehicle assembly (VA) (i.e., a reception pad in the VA) mounted on the EV makes an inductive resonance coupling with a transmission pad of the GA located in the charging station or the charging spot, and charges the battery in the EV using power transferred from the GA through the inductive resonance coupling. Thus, the most of EVs have the reception pad for the inductive resonance coupling with the transmission pad.
Meanwhile, the conventional electric vehicle charging system receives an alternating current (AC) input from an external power supply when performing the inductive charging or conductive charging, and converts it into a direct current (DC) to charge the high-voltage battery. Also, the output of the high-voltage battery may be used to charge an auxiliary battery charge and to drive various 12V electronic equipment via a low voltage DC-to-DC converter (LDC). However, such the structure is a main reason of lengthening a charging time required for charging the high-voltage battery.
For example, assuming that an external electric power of 2.2 kW (220V/10 A) is supplied to an EV and used to charge a high-voltage battery of the EV, approximately 360V/1˜2 A or more power from about 360V/6 A power which should be used to charge the high-voltage battery may be consumed for charging the auxiliary battery and driving the various 12V electronic equipment. This may correspond to ⅓ to ¼ of the actual charging power, which has a considerable influence on the charging time for the high-voltage battery.
Also, in the conventional technology, since it is possible to charge the high-voltage battery by using only one of the inductive charging and the conductive charging, both types of charging methods cannot be used simultaneously even when the EV has capabilities for both types. Therefore, it is very inefficient in terms of utilization of EV charging resources.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and may not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.